Silencer for boxcar retarders

ABSTRACT

A silencing structure is provided for use with a railcar retarder of the kind which includes a pair of opposed, wheelgripping, elongated jaws, the silencer effectively preventing the screeching noises that normally occur when the metallic wheels of the railcar pass between the opposed jaws. The silencer is comprised of a series of elongated ribs mounted on and extending longitudinally along one of the jaws and are arranged in a plurality of banks which are disposed to be in engagement with the wheels as the latter roll along the retarder. The banks of ribs are spaced relative to one another such that the wheels do not remain in contact with any one of the ribs a sufficient length of time for vibrations to develop which have a frequency great enough to produce the irritable screech normally associated with railcar retarders.

United States Patent 1191 Beck [ Oct. 30, 1973 1 SILENCER FOR BOXCAR RETARDERS [75 Inventor: George W. Beck, Tonganoxie, Kans.

[73 I Assignee: The Safety Skate Company, Inc.,

Tonganoxie, Kans.

[22] Filed: Aug. 21, 1972 [21] Appl. No.: 282,342

Related U.S. Application Data [63] Continuation-impart of Ser. No. 196,665, Nov. 8, 1971, Pat. No. 3,716,114, which is a continuation-in-part of Ser. No. 143,528, May 14, 1971, abandoned.

Primary Examiner-Duane A. Reger Attorney-Gordon D. Schmidt et al.

57 ABSTRACT A silencing structure is provided for use with a railcar retarder of the kind which includes a pair of opposed, wheel-gripping, elongated jaws, the silencer effectively preventing the screeching noises that normally occur when the metallic wheels of the railcar pass between the opposed jaws. The silencer is comprised of a series of elongated ribs mounted on and extending longitudinally along one of the jaws and are arranged in a plurality of banks which are disposed to be in engagement with the wheels as the latter roll along the retarder. The banks of ribs are spaced relative to one anothersuch that the wheels do not remain in contact with any one of the ribs a sufficient length of time for vibrations todevelop which have a frequency great enough to produce the irritable screech normally associated with railcar retarders.

11 Claims, 5 Drawing Figures PAIENIEnncI 30 ms a M 2 MED f\ 0 W 1 .JWZ wm lfilz 0 Fig. 3.

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SILENCER FOR BOXCAR RETARDERS CROSS REFERENCES This is a continuation-in-part of my copending application Ser. No. 196,665, filed Nov. 8, 1971, now U. S. Pat. No. 3,716,114, and entitled Silencer For Railcar Retarders which, in turn, is a continuation-in-part of my copending application Ser. No. 143,528, filed May 14, 1971, and entitled Silencer For Railroad Boxcar Retarders, now abandoned.

This invention relates to a silencer for use in conjunction with a railcar retarder as is well-known and in common use in the railroad industry. The purpose of the retarder is to slowdown and/or stop the movement of railcars as they are transferred from one location to another within a railroad yard as, for instance, during the assembling of trains.

In view of the fact that the brakes of respective railcars are not operable during most spotting operations, auxiliary devices such as retarders are used to control the movement of the cars. This is particularly true when the cars are humped," i.e. permitted to freewheel down an incline to a point of assembly. The retarder relies entirely on a clamping action to grip the railcar wheels as they pass therethrough and the resulting metal-on-metal frictional engagement of the rotating wheel with the stationary retarder causes the highly undesirable screeching noise. This problem has been made more noticeable through the increased awareness and concern for noise pollution, particularly in those areas where a high concentration of such devices are in use, as in the aforementionedswitching yards.

Accordingly, it is a .very important objectof my invention to provide a railcar retarder silencer that effectively prevents the creation of undesirable noiseproducing vibrations as the wheels are gripped by the retarder.

Another important object of the invention is to provide a silencer in which the wheels are engaged by a series of .spacedsurfaces of sufficient combined length to exert an adequate braking or stopping action on the railcar, while at the same time the length of any one individual surface is sufficiently short to break contact with the wheel before any vibrations are created which are of a 1 frequency capable of producing harmful sounds.

A still further important object of the invention is to provide a silencer which is so constructed that any heat buildup resulting from the frictional contact between the silencer and the wheel is quickly dissipated to prevent overheating of the retarder.

Yet another object of the invention is to provide a silencer in which the effective life of the wearing portions thereof is greatly improved over that of other currently known silencers. 7 Still a further important object of the invention is to provide a railcar silencer which is capable of resisting the shearing action imparted thereto by the rotating wheel as the latter comes into contact therewith.

In the drawing:

FIG. 1 is a fragmentary, plan view showing a retarder installed on a section of rail and having a silencer made pursuant to the present invention and illustrating a railcar wheel gripped between the jaws;

FlG. 2 is an enlarged,-transverse, cross-sectional view showing the jaws in their normal positions;

FIG. 3 is a vertical, cross-sectional view similar to FIG. 2 taken along line 33 of FIG. 1 showing a wheel between the jaws;

FIG. 4 is an enlarged, fragmentary, detailed, side elevational view, parts being broken away to show details of construction; and

FIG. 5 is a fragmentary, slightly enlarged, side elevational view showing the side opposite that seen in FIG. 4, parts being broken away for clarity.

An apparatus in the nature of a railcar retarder, broadly designated by the numeral 10, is adapted to be attached to a section of rail 12. The retarder 10 is provided with a pair of opposed, elongated, spring-loaded, essentially T-shaped jaws l4 and 16 between which the hardened metallic wheels 18 of a railcar pass l0ngitudinally therebetween. A noise-silencing structure 20 having a plurality of elongated ribs 22 arranged in a series of banks 24 is mounted on the jaw 16 in longitudinally, spaced-apart relationship such that the ribs 22 are disposed for contact by the wheels 18 as the latter pass between the jaws 14 and 16.

The retarder 10 is attached to a web 28 of the rail 12 through the use of L-shaped brackets 30 which are positioned in pairs, as well as in opposing relationship to opposite sides of the rail 12. The brackets 30 are horizontally spaced along the rail 12 and each pair pivotally supports an arm 32. The arms 32 in turn, cooperate to support their corresponding jaws 14 and 16 to maintain the same in spaced, parallel relationship to the rail 12. A compression spring 36 is interposed between the lower ends of the arms 32 and is held therebetween by nut and bolt means 38. The spring 36 and bolt means 38 are located beneath the rail 12 so that the pivot arms 32 act as levers and the pins 34 become the fulcrum points for holding the jaws l4 and 16 in their normal positions as seen in FIG. 2.

The jaws l4 and 16 are provided with substantially upright flanges 40 and 42 respectively and with generally horizontally positioned leg portions 44 and 46 respectively. The jaws l4 and 16 are releasably attached to their respective pivot arms 32 by nut and bolt means 48 in such a manner that they are substantially above and to the side of the rail 12 with their respective flanges 40 and 42 disposed between the arms 32 and the rail 12.

The ribs 22 making up each of the banks 24 are vertically aligned and have their longitudinal axes in parallelism with the longitudinal axis of the jaw 16. The ribs 22 may be in the form of a hightensile alloy stainless steel rod welded to a mounting pad 26 making up a part of the bank 24 or, depending on the type of fabricating equipment available, may be cast or roll-formed as an integral part of the pad 26 at the factory, thus eliminating the need for welding. Another alternate manner in which the ribs 22 might'be formed would be to provide a plurality of weld beads on the pad 26, using a welding rod containing a high tensile alloy stainless steel. ln each case, the material from which the ribs 22 are made is considerably harder than that from which the wheel 18 is made.

A series of the pads 26 are attached, as by welding, to an elongated support 50 which, in turn, is releasably attached to the flanges 42 through the use of plow bolts 52 which cooperate with corresponding countersunk holes in the support 50 to present a flush surface 53. It is suggested that the thickness of the support 50 be 9% inch or more, while the width thereof may vary from 3% to 6 inches, depending on the size of the flanges 42 to which it is being attached. Furthermore, the support 50 may be of any convenient length compatible with ease of installation or replacement, it being noted that the retarders generally vary in length from 29 to 50 feet, depending on use requirements.

Sound tests have revealed that ideally, the length of the individual ribs 22 should be less than 6 inches but more than 3 inches. The tests have shown that the vibration frequencies which produce the undesirable screeching noise are not attained until the wheel 18 has been in engagement with the retarder 10 for a certain minimum period of time. Thus, the limiting of the time that the wheel 18 is in engagement with any one rib 22 to something less than this predetermined period of time effectively prevents the vibrations from reaching a frequency sufficiently great to produce the undesirable noises.

Accordingly, it has also been shown that the ideal longitudinal spacing between the ribs 22 is 3 inches, although it could vary from 3% to 3% inches without materially reducing the car-stopping capability of the retarder. This spacing is sufficient to break up any vibration buildup in either the wheel 18 or the retarder 10 before any given point on the wheel 18 reestablishes contact with another one of the ribs 22. The 3 inch spacing also provides for at least three longitudinally spaced lengths of ribs 22 tobe in separate yet simultaneous engagement with the wheel 18, thereby providing a minimum of 18 inches'of continuous rib contact with the wheel 18 during the time the latter is being gripped by the jaws 14 and 16. Experience has shown that, depending on the adjustment of the springs 36, anywhere 'from 7-70 tons of pressure is exerted on the wheel 18 as it moves through the retarder 10.

The vertical spacing between the ribs 22, as well as the horizontal spacing between the banks 24, also allows for the rapid dissipation of the heat created during the frictional engagement of the ribs 22 with the wheel 18 by permitting air circulation around the ribs and thereby prevents the retarder 10 from becoming overheated as a result of the steel-on-steel rubbing action.

In operation, a plurality of retarders 10 are provided at those points along the railroad track where it is desired to stop or otherwise control the railcars. While the drawing illustrates only one retarder 10, it is to be understood that a retarder is placed on each rail 12 of the track in parallel, side-by-side relationship so that the wheels on both sides of the car are gripped simultaneously. The ribs 22 engage an annular, circumferential flange 54 on the inner side of the wheel 18, while the jaw 14 engages an annular rim or ring 56 on the outer face of the wheel 18 and which is normally considerably narrower than the flange 54 to present a relatively small zone of contact, indicated by the numeral 58, as compared to a larger zone of contact 60 presented by the flange 54. Originally, retarders 10 were comprised of identical inner and outer jaws similar to jaw 14 and were actually sections of rail in which one of the base flanges had been removed. However, because of the practical need for easily attaching the silencer, the inner jaw 16 as here shown, replacesthe original jaw and is constructed of half inch material in order to provide a stiffness approaching that of the 151 pound rail used for the outer jaw 14. It has been found that when lighter material is used, the jaw will flex excessively as the wheels 18 transit the retarder. It is also important that there not be any upright flanges such as might be used for structural reinforcement at the end of the legs 44 and 46 opposite flanges 40 and 42 respec tively. The area immediately above these ends must be kept clear so as not to interfere with the undercarriage of the railcar.

As the freewheeling railcar approaches the set of retarders, the wheels 18 are guided into contact with the jaws 14 and 16 by angled leader sections 62 which are provided at each end of the jaws (shown only at one end in FIG. 1). As the wheel 18 moves through the retarder 10 it comes into successive momentary contact with each of the banks 24 of the ribs 22 which frictionally engage the rotating wheel at the zone 60, the retarder 10 being in a gripping position as best seen in FIG. 3. While the present disclosure illustrates use of the structure 20 on only one side of the wheel, it is to be understood that, depending on conditions of use, such as in a humping operation, a second structure may be provided which would engage the opposite side of the wheel 18. The jaws 14 and 16 return to their normal positions as illustrated in FIG. 2 after the railcar has moved through the retarders 10.

Therefore, .it is to be recognized that a significant contribution has been made to the problem of noise pollution, particularly with respect to railroad operations. While a complete scientific explanation has not been set forth as the invention 1 is hereinabove described, it is believed that its success in effectively reducing the noise level of the interaction of a rotating wheel with a retarder is because the resultant vibrations are interrupted or stopped before they are allowed to reach a frequency which produces the objectionable sounds. In other words, rather than attempting to muffle or stifle the screeching noise, the present invention eliminates the source of the noise before it becomes objectionable. It is to be further recognized that this limiting of contact to minimize the undesirable vibrations has been accomplished while still effectively providing sufficient pressure and engagement with the rotating wheels to adequately control and stop the large and massive railcars.

Having thus described the invention, what is claimed as new anddesired to be secured by Letters Patent is:

1. In combination with apparatus for retarding movement of a car along a rail of the kind which is provided with a pair of opposed, elongated, spring-loaded jaws between which the metallic wheels of the car pass in engagement with the jaws longitudinally thereof, structure for substantially eliminating noise incident to such retardation, said structure including: i

a series of elongated ribs mounted on one of said jaws, i

said series extending longitudinally of said one jaw,

said ribs being spaced apart longitudinally of the jaw and being disposed for contact by the wheels of the car passing between the jaws.

2. A structure as claimed in claim 1, wherein the longitudinal axes of said ribs are in parallelism with the longitudinal axis of said one jaw.

3. A structure as claimed in claim 1, wherein said ribs are appreciably more wear-resistant than said wheels.

4. A structure as claimed in claim 1, wherein a plurality of said ribs are incontact with one of said wheels when the latter is in full engagement with said jaws.

5. A structure as claimed in claim 1, wherein a plurality of said series are disposed in vertically spaced relationship to one another.

6. A structure as claimed in claim 5, wherein said plurality of series are vertically aligned to present banks of ribs.

7. A structure as claimed in claim 6, wherein the longitudinal axes of said ribs are in parallelism with the longitudinal axis of said one jaw.

8. A structure as claimed in claim 6, wherein there is provided a mounting pad for each of said banks.

9. A structure as claimed in claim 8, wherein said pads are carried by a support; and means releasably attaching said support to said one jaw.

10. In combination with apparatus for retarding movement ofa car along a rail of the kind which is provided with a pair of opposed, elongated, spring-loaded jaws between which the metallic wheels of the car pass in engagement with the jaws longitudinally thereof, structure for substantially eliminating noise incident to such retardation, said structure including:

a series of pads mounted on one of said jaws, said series extending longitudinally of said one jaw, said pads being spaced apart longitudinally of the jaw and being disposed for contact by the wheels of the car passing between the jaws. 11. A structure as claimed in claim 10, wherein is provided a plurality of wheel-engaging ribs on each pad respectively. 

1. In combination with apparatus for retarding movement of a car along a rail of the kind which is provided with a pair of opposed, elongated, spring-loaded jaws between which the metallic wheels of the car pass in engagement with the jaws longitudinally thereof, structure for substantially eliminating noise incident to such retardation, said structure including: a series of elongated ribs mounted on one of said jaws, said series extending longitudinally of said one jaw, said ribs being spaced apart longitudinally of the jaw and being disposed for contact by the wheels of the car passing between the jaws.
 2. A structure as claimed in claim 1, wherein the longitudinal axes of said ribs are in parallelism with the longitudinal axis of said one jaw.
 3. A structure as claimed in claim 1, wherein said ribs are appreciably more wear-resistant than said wheels.
 4. A structure as claimed in claim 1, wherein a plurality of said ribs are in contact with one of said wheels when the latter is in full engagement with said jaws.
 5. A structure as claimed in claim 1, wherein a plurality of said series are disposed in vertically spaced relationship to one another.
 6. A structure as claimed in claim 5, wherein said plurality of series are vertically aligned to present banks of ribs.
 7. A structure as claimed in claim 6, wherein the longitudinal axes of said ribs are in parallelism with the longitudinal axis of said one jaw.
 8. A structure as claimed in claim 6, wherein there is provided a mounting pad for each of said banks.
 9. A structure as claimed in claim 8, wherein said pads are carried by a support; and means releasably attaching said support to said one jaw.
 10. In combination with apparatus for retarding movement of a car along a rail of the kind Which is provided with a pair of opposed, elongated, spring-loaded jaws between which the metallic wheels of the car pass in engagement with the jaws longitudinally thereof, structure for substantially eliminating noise incident to such retardation, said structure including: a series of pads mounted on one of said jaws, said series extending longitudinally of said one jaw, said pads being spaced apart longitudinally of the jaw and being disposed for contact by the wheels of the car passing between the jaws.
 11. A structure as claimed in claim 10, wherein is provided a plurality of wheel-engaging ribs on each pad respectively. 